Software testing is an integral part of the software development process, primarily concerned with evaluating software products and items/components to detect differences between a particular input and the expected output. Testing is likewise done to assess the different features of a software item as well as the overall quality of the product. It is a verification process that must be done during development to ensure the validity, effectiveness, and quality of the end product.
Verification is a software testing process that ensures that the product satisfies all conditions imposed right at the start of the design and development phase. It is during the verification process that developers determine whether or not the software behaves the way it is supposed to. Validation, on the other hand, ensures that the product satisfies all specified requirements as per customer requirements at the end of the development phase.
Two basic techniques are used in software testing, the first of which is blackbox testing, which ignores the internal mechanisms of the application system and instead focuses on the output it generates. It is otherwise called functional testing. The second basic technique is known as white box testing, which conversely takes into account the internal mechanisms of a software system. Otherwise called glass box or structural testing, it is more concerned about the components (means) of the system rather than its outputs (ends). In general, black box testing is used for validation, while white box testing is used for verification.
Software testing methods vary widely, depending on the type of software being tested or verified as well as the part, component, or feature of the application being tested. Some of the most common types of software testing methods include unit testing, integration testing, functional testing, system testing, stress testing, performance testing, usability testing, acceptance testing, regression testing, and beta testing among others.